Circuit-breaker



C. T. EVANS.

CIRCUIT BREAKER.

APPLICATION FILED JU'NEZE, 1917.

Patented Nov. 30, 1920..

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UNITED STATES Prrrleila'r OFFICE.

CLARENCE T. EVANS, 0F MILWAUKEE, WISCONSIN, ASSIGNORTO THE'CUTLER-HAMMER MFG. CO., 0F MILWAUKEE, WISCONSIN, A CORPORATION OF WIS- CON SIN.

CIRCUIT-REAKER.

y Specification of Letters Patent. Patentd NOV, 30, y192() Applicationled .Tune 28, 1917. Serial No. 177,455.

To all whom t may concer-n.' l

Be it known that I, CLARENCE T. EVANS, a citizen of .the United States,resi-ding at Milwaukee, in the county ot Milwaukee and State ofllVisconsin,i have invented new and useful lmprovements inCircuit-Breakers, of which thefollowing is a full, clear, cnoise, andexact-description, reference being had to the accompanyingdrawing,forming a part otl this specification.

This invention relates to circuit breakers and more particularly tothose which are non-closable on overload.

In circuit breakers of the aforesaid character it has heretofore beenproposed to provide a collapsible connection between the movable switchmember and the operating means therefor and to render said connectioninoperative for' maintaining the switch closed during overloads, and thepresent invention. has among its purposes to obviate the necessity forsuch collapsible connection.

A further object is to provide a circuit breaker of simple construction,comprising few and rugged parts, which, moreover, is positive and whollyreliable in its action.

Other objects and advantages will hereinat'terr appear.

The accompanying drawing is a side elevational view partly .in section,of an embodiment-ot said invention.

Referring to the drawing, the same illustrates a pair of switch arms 1and 2 pivotally mounted in suitable relation to make and break anelectric circuit through a pair of contacts 3 and 4 carried at theirrespective tree ends, the arm 1 being biased to open circuit position bygravity or otherwise and being normally retained in closed c ircuitposition by a spring-pressed latch 5 subject, however, to release by aplunger 6 actuated by an overload tripping coil 7, the afore-describedparts being supported in suitable operative relation upon an insulatingpanel 8 and inclosed within a suitable casing 9.

The switch arm 2 is providedwvith an operating shaft 10 carrying arigidly secured handle 11 located outside the casing 9 whereby theswitch may be actua-ted manually, said handle being arranged to act asan over,- balancing weight for maintaining said arm in either closedcircuit or open circuit position. A link 12 having an insulating section13,'is pivoted at 14 to said arm and engages the arm 1 by means of alost motion connection comprising a pin 15 projecting within a slot 16whereby upon opening of the switch in response to overload, said lastmentioned arm may be restored t0 closed circuit position by upwardmovement of the f sponse to its bias, thus preventing permanent closureof the switch under such condic tions. l

-More particularly the switch arm 2 is plvoted upon a support" 17projecting ,from

the base 8, said arm being provided with a stop 18 to limit downwardmovement thereof. The arm 1` is similarly pivotcd at 19 upon a support2O` also carried by the base and provided with a stop 21 to limitdownward movement of said arm. The contact 3 is resiliently mounted uponsaid arm and is preferably insulated therefrom by'means ot' a suitablenon-conductive medium interposed therebetween.

The 'latch 5 is pivoted at 22 upon the support 20 the upper end of saidlatch being shaped to engage a pin 23 projecting from the side of thearm 1 while a helical spring 24 biases said latch to engagementtherewith, movement of said latch in response to its bias being alsolimited by the stop member 21.

The tripping coil is of known construction and comprises a U-shapedmagnetic support 25 secured to the base 8 below the switch mechanism andcarrying the usual coil and plunger, the Jformer being connected in thecontrolled circuit and provided with Calibrating means of knowncharacter, and 'the latter being arranged to engage and trip the latch 5upon response of said coil to overloads.

, 1t is to be understood that during movement of the operating handle 11to return the arm` 1 to closed'circuit position, the arm 2 is moved toopen circuit position whereby engagement ot the switch contacts duringsuch' operation is positively prevented.' Furthermore, upon subsequentmovement of the arm 11 to closed circuit position, the

slotted portion 16 of the link 12 is moved downwardly to disengage thepin 15 for permitting opening movement of the arm 1 upon tripping of thelatch.

IVhile the aore-described switch is'single pole, it is obvious that theconstruction is equally adaptable to switches of the multipole type.

IVhat I claim as new and desire to secure by Letters Patent is:

1. In a circuit breaker, the combination with a pair of cooperatingcontact elements, one of said elements having means for moving the sameout of engagement with the other and means biasing the same to aposition of engagement with the other and the other of said elementsbeing also movable and tending at all times to disengage they former, ofmeans to restrain said other element against such tendency but subjectto automatic release under overload conditions.

2. In a circuit breaker, in combination, a

pair of contact elements adapted to coperate electrically, one or" saidelements being permanently biased to disengage thelother and havingretaining means to hold the same against such bias, the other of saiddevices being oppositely biased dependent upon its position withreference to a predetermined neutral position to move either toward oraway from said former element when so held, overload tripping means forsaid former element and means whereby said former element maybe resetafter tripping thereof, by movement of said latter element to circuitinterrupting position.

8. In a circuit breaker, in combination, a pair of contact armsextending substantially at right angles to each other and carryingcontacts adapted to coperate electrically, one or said contacts beingspring-biased t0- ward the other, the arm carrying said contact beingpermanently biased to cause separation of said contacts'as abutmentcontacts, means for restraining said arm against such bias subject torelease upon the occurrence of an overload, the'other of said armshaving a bias to contact engaging position and being movable from suchposition or returnable thereto to effect sliding engagement of saidcontacts.

4:. In a-circuit breaker, in combination, a pair of movable switch armslcarrying contacts adapted to coperate electrically, one of said contactsbeing spring pressed, said arms and said contacts beingarrangedrelatively to one another to provide for wiping engagement ofthe latter and separation thereof as abutment contacts, one of said armshaving a bias toward engaging position and the other of said arms beingpermanently biased to cause separation of said contacts and means forrestraining said latter arm against such bias subject to trippingthereof under predetermined conditions of overload.

5. In a circuit breaker, in combination, a pair of movable switch armscarrying contacts adapted to coperate electrically, one of said contactsbeing spring pressed, said arms and said contacts being arrangedrelatively to one another to provide for wiping engagement of the latterand separation thereof as abutment contacts, one of said arms having abias toward Contact engaging position and the other of said arms beingpermanently biased to cause separation oit' said contacts and means forrestraining said latter arm against such bias Subj ect to trippingthereof under predetermined conditions of overload,

and resetting means for said latter arm including a link having a pinand Slot connection therewith and a pivotal connection with said formerarm for moving said latter arm to closed position during movement ofsaid former arm to open circuit position and permitting return of saidformer arm to closed circuit position during restraint of said latterarm by said restraining means.

In witness whereof I have hereunto subscribed name.

CLARENCE T. EVANS.

